Sole structure

ABSTRACT

The present invention relates to a sole structure ( 10 ) comprising an outsole ( 31 ) and a midsole ( 33 ) and an insert member ( 4 ), between said outsole and said midsole. The insert member comprises at least a cage portion ( 410 ) having a first cavity ( 41 ) that accommodates a cushion member ( 5 ). The midsole comprises a second cavity ( 330 ), in which said cushion member can be at least partially inserted.

The present invention relates to an improved sole structure. More particularly, the present invention relates to a sole structure, which has improved capabilities in terms of shock absorbing and comfort for the user's foot.

As is widely known, a conventional shoe generally comprises an upper that is associated to a sole structure.

The sole structure typically comprises an outsole provided with a tread in contact with the ground, a midsole for supporting the user's foot and one or more insoles for a better comfort of the user's foot.

The sole structure may often comprise additional elements such as a shank member and a counter member, which are positioned respectively at the arch plantar and at heel region of user's foot for providing additional support.

As is known, shock absorbing capabilities are an important factor to consider in a sole structure, particularly when the shoe is addressed to the exploitation of sports activities.

For this reason, shoe technology has been constantly focused on the development of sole arrangements aimed at providing a shock absorbing action.

In most sole structures, a shock absorbing body is adopted, which consists of a shaped piece of an elastomeric material, such as polyurethane or soft rubber, that is received in a recess formed in the outsole, under the midsole, typically at the heel region of the user's foot.

Unfortunately, these traditional constructions provide a poor and not really perceivable shock absorbing effect and reveal severe limitations in terms of robustness and stress resistance. The midsole itself prevents from the obtaining of an effective dampening of shocks, since it constitutes a separation element between the user's foot and the shock absorber.

In some known sole structures, the shock absorbing body has a channeled structure, which comprises a plurality of vertical channels, in which a filler material is arranged. This arrangement is characterized by a relatively poor level of compressibility in a direction towards the ground, since the vertical channels are defined by a support lattice having walls oriented in the same direction of the pressure exerted by the user's foot. This fact constitutes a severe limitation to shock absorbing performances.

In patent application US2008/0115389A1, the shock absorbing body has a cellular structure, which is instead horizontally oriented and defines different levels of cells that are filled with a filler material, such as gel, silicone, polyurethane resins or soft rubber.

This solution has the drawback of entailing an increased thickness for the sole structure, since multiple levels of cells are needed for providing a satisfactory shock absorbing effect. The distance between the user's foot and the ground thus increases with detrimental effects for the user's balance and step control.

In addition, this sole structure has revealed to be quite complex to arrange and relatively expensive to manufacture at industrial level.

From the considerations above, it is apparent that there still is a largely felt need for sole structures, which are capable of providing a remarkable shock absorbing effect and, more in general, a high level of comfort for the user's foot, while being quite easy to manufacture at industrial level with relatively low costs and labor.

The main aim of the present invention is to provide a sole structure, which allows the overcoming of the drawbacks of the state of the art and the satisfaction of such a need.

This aim is achieved, according to the invention, by a sole structure according to the following claim 1.

In its more general definition, the sole structure, according to the invention, comprises an insert member, which is positioned between the outsole and the midsole and comprises at least a cage portion, positioned at the heel region of the user's foot.

The cage portion comprises a first cavity, which accommodates at least partially a cushion member, which can be at least partially inserted in a second cavity of the midsole.

The sole structure, according to the invention, has improved capabilities in terms of shock absorbing and support to the user's foot and, at the same time, it is quite robust and simple to manufacture.

Other features and advantages of the sole structure, according to the present invention, will become apparent from the following description of preferred embodiments, taken in conjunction with the drawings, in which:

FIG. 1 is a perspective view of a sports shoe, comprising the sole structure, according to the invention; and

FIG. 2 is a perspective partial view of the sole structure, according to the present invention, in a first embodiment; and

FIG. 3 schematically shows an exploded view of the sole structure, according to the present invention, in said first embodiment; and

FIG. 4 schematically shows a partial lateral view of the sole structure of FIGS. 2-3; and;

FIG. 5 schematically shows a partial sectional view of the sole structure of FIGS. 2-3; and;

FIG. 6 is a partial lateral view of the sole structure, according to the present invention, in a further embodiment; and

FIG. 7 schematically shows a partial exploded view of the sole structure of FIG. 6.

Referring now to the cited figures, the present invention relates to a sole structure 10, which is normally associated to an upper 11 defining a volume for receiving the user's foot, thereby forming a shoe 100.

The sole structure 10 comprises an outsole 31, which may comprises a tread 313 that may have different shapes, according to the needs.

In the cited figures, the outsole 31 is divided in two distinct pieces 311 and 312 that are positioned respectively at the heel region 100A and the toe region 100C of the user's foot.

According to the needs, the outsole 31 may instead comprise a unique piece that covers also the arc plantar region 100B.

At the heel region 100A, the outsole 31 may preferably comprise a window (not shown) and/or it may be of a transparent material, so as to allow internal inspection.

The outsole 31 may be made of a polymeric material resistant to wear, such as rubber, thermoplastic rubber, thermoplastic polyurethane or other polyurethane materials.

The sole structure 10 comprises a midsole 33, which extends above the outsole 31, so as to provide support to the user's foot.

The midsole 33 is preferably made of Ethylene Vinyl Acetate (EVA) and comprises a lower surface 332 and an upper surface 331.

The sole structure 10 preferably comprises also one or more insoles 150 (shown in FIG. 3 only), which lay above the midsole 33, within the volume defined by the upper 11 and which are preferably removable.

The sole structure 10 comprises an insert member 4, which is positioned between the outsole 31 and the midsole 33, at least at the heel region 100A.

The insert member 4 comprises at least a cage portion 410, which is positioned at the heel region 100A.

Preferably, said cage portion 410 is made of a unique piece of relatively rigid plastic material, e.g. a polyurethane material.

As an alternative, the cage portion may be obtained by overlapping a plurality of relatively rigid shells.

Advantageously, the cage portion 410 may be integral with a shank portion 420, which is positioned at the arch plantar region 100B.

As an alternative, the shank portion 420 may be provided as a separated piece that is operatively associated to the insert member 4 and/or the outsole 31.

The cage portion 410 comprises a first cavity 41, which preferably extends in a direction substantially perpendicular to the ground.

The first cavity 41 preferably comprises a bottom end 41A, at which a bottom wall 414 is provided. The bottom wall 414 optionally comprises a window (not shown) and/or it may be of a transparent material.

At an upper end 41B, the first cavity 41 is instead fully or partially open towards the midsole 33.

The midsole 33 comprises a second cavity 330 that is arranged substantially aligned with said upper end 41B, so as to communicate with the first cavity 41.

The second cavity 330 is preferably a hole that passes through the entire thickness of the midsole 33 between the surfaces 331 and 332.

In this case, the first cavity 41 will be in communication with the internal volume of the shoe 100, which is defined by the upper 11.

In a possible option (not shown), the second cavity 330 may be upwardly closed by a layer of material, associated to the midsole 33, or by a wall that is integral with the midsole 33.

Preferably, said layer of material (or said wall) is relatively thin and flexible. Such a layer of material may be also at least partially removable.

The cage portion 410 preferably comprises a first lateral wall 411 that may have a horseshoe shape, with the cavity oriented towards the toe region 100C.

The lateral wall 411 has an internal surface 412, which laterally defines at least partially the perimeter of the first cavity 41, and an external surface 413, which defines at least partially the contour of the sole structure 10 at the heel region 100A.

The cage portion 410 preferably comprises also a second lateral wall 415, which has an arched shape with its convexity directed towards the toe region 100C. The lateral wall 415 advantageously defines the remaining perimeter of the first cavity 41.

In an alternative embodiment (not shown), the first cavity 41 may be laterally defined by a unique lateral wall having an annular shape.

The cage portion 410 preferably comprises one or more third cavities 43, which communicate with the first cavity 41 and advantageously extend at least partially through the first lateral wall 411.

Preferably, the third cavities 43 are holes passing through the entire thickness of the first lateral wall 411 from the internal surface 41 to the external surface 413, so as to put the first cavity 41 in communication with the external environment.

As an alternative, the third cavities may be closed at the end 43A (FIG. 2) that is positioned opposite with respect to the first cavity 41.

The first cavity 41 and the third cavities 43 extend along directions that are not parallel, preferably perpendicular.

Preferably, each side of the lateral wall 411 comprises a plurality of parallel third cavities 43 that have a substantially tubolar shape, as shown in FIGS. 1-5.

In an alternative embodiment of the sole structure 10, shown in FIGS. 6-7, the cage portion 10 comprises two elongates cavities 43, each positioned at one side of the first lateral wall 411.

In further alternative embodiments (not shown), the third cavities 43 may be also positioned along the second lateral wall 415 or along both the walls 411 and 415.

In general, the shape of the third cavities 43 may be any, according to the needs, as well as their position along the lateral wall 411 and/or 415.

The first cavity 41 accommodates at least partially a cushion member 5, which preferably comprises a main body 51 having at least an upper portion 510 that is or can be at least partially accommodated in the second cavity 330.

Advantageously, at the upper portion 510, the cushion member 5 is capable to enter in contact with the user's foot or with an insole 150.

When the cavity 330 is a hole passing through the thickness of the midsole 33 an advantageous direct contact is realized between the cushion member 5 and the user's foot or the insole 150.

When the cavity 330 is upwardly closed by a thin and flexible layer or wall, an indirect contact is obtained.

In both these cases, the user's foot can benefit from an improved cushioning effect, since the pressure of the user's heel is directly exerted on the cushion member 5 and not on the midsole anymore. In this manner, the midsole 33 does not attenuate at all the cushioning effect offered by the cushion member 5.

As shown in FIG. 2, the upper portion 510 is preferably inserted in the cavity 330, so as to slightly protrude from the upper surface 331. This solution remarkably facilitates the realization of a contact between the cushion member 5 and user's foot or the insole 150.

According to this preferred embodiment, the upper portion 510 may be shaped according to a slightly rounded profile, as shown in FIG. 5, a stepped profile, so as to ensure a good coupling with the lateral wall of the second cavity 330 or a mushroom profile, so as to ensure a good coupling with the upper edge of the second cavity and with the upper surface 331 of the midsole 33.

Alternatively, the upper portion 510 may be inserted in the second cavity 330, so as to stay at the same level with respect to the upper surface 331 of the midsole 33.

As a further alternative, the upper portion 510 is only partially inserted in the second cavity 330,

As a yet further alternative, the upper portion 510 may be positioned outside the cavity 330 and be aligned with it.

In all these alternative embodiments (not shown), the pressure of the user's foot will cause the full insertion of the upper portion 510 in the second cavity 330 and its protrusion from the upper surface 331 of the midsole 33, thus forcing the cushion member 5 to enter in contact with the user's foot or the insole 150.

The cushion member 5 comprises also one or more lateral portions 520, which are preferably accommodated at least partially in the third cavities 43 and which are advantageously shaped, so as to match with the internal profile of the third cavities 43.

The cushion member 5 is thus arranged, so as to be capable to change its volume in a predefined manner when a pressure is applied on it, and more particularly, to expand along one or more predefined directions 200 not parallel and preferably perpendicular with respect to the direction 201, along which pressure of the user's foot is applied.

Preferably, the cushion member is arranged so as to be capable of expanding along one or more directions 200 that are horizontal with respect to the ground while the pressure on it is exerted along a vertical direction 201.

It should be noticed how the third cavities 43 help this anisotropic expansion since they provide the cushion member 5 with predefined expansion routes.

Thus, when pressure is applied (e.g. because the user leans his foot on ground) the cushion member 5 may expand through the third cavities 43. Conversely, when pressure is released (e.g. because the user lift his foot from ground) the cushion member 5 may recover at least partially its initial volume.

The cushion member 5 is preferably made of a gel material, an impact-resistant elastic material (e.g. d3o™) or an elastomeric material.

According to an embodiment of the present invention, the cushion member 5 consists of a shaped pad that is filled with a gel material. This solution allows a quicker expansion of the cushion member 5 when a pressure is exterted on it.

The cushion member 5 may also comprise a plurality of portions made of different materials and/or made of the same material having different densities, such as a plurality of layers of different materials, which are overlapped or positioned side by side.

As an example, the upper portion 510 may comprise a layer of gel, which is injected over the main body 51 that comprises a different material or a gel having a different density. Of course, other combinations of layers and/or materials are possible.

In another example, the main body 51 may be formed by a plurality of vertical layers of different materials, which have a cylindrical geometry and are positioned according to a concentric layout.

The sole structure, according to the invention, allows to achieving the intended aim and objects.

The sole structure 10 comprises the insert member 4 having the cage portion 410 that comprises a cavity 41 for accommodating the cushion member 5 and defined by one or more lateral walls.

This allows to have a relatively small thickness of the sole structure 10 at the heel region 100A and at the same time to provide support to the user's foot.

The midsole 33 is provided with the second cavity 330, through which the cushion member 5 can be inserted.

This feature allows to bring the cushion member in direct contact with the user's foot or with an internal insole.

Thus, the presence of the midsole 33 does not anymore constitute an obstacle to the achievement of a maximum shock absorbing and cushioning effect.

The cushion member 5 may expand along predefined directions, preferably perpendicular to the pressure applied. This allows a further improving of the shock absorbing effect.

The cage portion 410 of the insert member 41 is structured with the third cavities 43, so as to help this anisotropic expansion of the cushion member 5 while providing support to the user's foot at the same time.

Manufacturing tests have proven that the sole structure 10 according to the present invention, can be assembled in a simple manner, particularly at industrial level. This feature allows to remarkably reducing the manufacturing costs. 

1. A sole structure (10) comprising an outsole (31) and a midsole (33) and an insert member (4), which is positioned between said outsole and said midsole, characterized in that said insert member comprises at least a cage portion (410), which is positioned at the heel region of the user's foot, said cage portion comprising a first cavity (41), which accommodates at least partially a cushion member (5), said midsole comprising at least a second cavity (330), in which said cushion member can be at least partially inserted.
 2. A sole structure according to claim 1, characterized in that said cushion member is capable to enter in contact with the user's foot or with an insole (150) of said sole structure.
 3. A sole structure according to claim 2, characterized in that said second cavity is a hole which passes through the entire thickness of said midsole.
 4. A sole structure according to claim 3, characterized in that said cushion member is inserted through said hole, so as to be capable to enter in contact with the user's foot or with an insole (150) of said sole structure.
 5. A sole structure according to claim 1, characterized in that said cage portion comprises at least a first lateral wall (411) having an internal surface (412), which defines at least partially the perimeter of said first cavity.
 6. A sole structure according to claim 1, characterized in that said cage portion comprises at least a third cavity (43), which communicates with said first cavity.
 7. A sole structure according to claim 5, characterized in that said third cavity extends at least partially through said first lateral wall.
 8. A sole structure according to claim 7, characterized in that said third cavity extends through said first lateral wall from the internal surface to an external surface (413) of said first lateral wall.
 9. A sole structure according to claim 6, characterized in that said third cavity has a tubular shape.
 10. A sole structure according to claim 6, characterized in that said third cavity has an elongated shape.
 11. A sole structure according to claim 1, characterized in that said cushion member can expand at least partially along at least a predefined direction when a pressure is applied on said cushion member.
 12. A sole structure according to claim 6, characterized in that said cushion member is capable of expanding at least partially along said third cavity when a pressure is applied on said cushion member.
 13. A sole structure according to claim 11, characterized in that said cushion member is at least partially inserted through said third cavity.
 14. A sole structure according to claim 1, characterized in that said cushion member is made of a gel material or an elastomeric material or an impact resistant material.
 15. A shoe (100) characterized in that it comprises a sole structure (10) according to claim
 1. 